1. Field of the Invention
This invention relates to finder systems, and more particularly to finder systems having interchangeable components of different refracting power to change the magnification power of the entire system.
2. Description of the Prior Art
Known prior art cameras have a number of inter-changeable objective lenses, for example, standard and telephoto lenses, to permit shooting with two or more different focal lengths. In such a prior art camera, it is desirable to make the magnification of an object image and the angular field coverage of the finder coincide with those on the film plane as the focal length of the objective lens changes.
For example, discretely changeable magnification power finder systems of the reverse Galilean type are known from Japanese Laid-Open Patent Application No. 52-137331, Japanese Utility Model Application No. 54-66541 and U.S. Pat. No. 4,277,158. The operating mechanism for these finder systems is, however, quite complicated, because changing of the magnification power requires axially displacing the two components constituting the objective lens while retracting the other component from the optical path.